EP 0270534 B1 19930107 - RESOLUTION CONVERSION OF BITMAP IMAGES USING ERROR TERM AVERAGING
Title (en)
RESOLUTION CONVERSION OF BITMAP IMAGES USING ERROR TERM AVERAGING
Publication
Application
Priority
US 8601365 W 19860626
Abstract (en)
[origin: WO8800377A1] A system for converting an input bitmap image (12) of one resolution to an output bitmap image (14) of a different resolution. A mapping (10) is defined between pixels in the input bitmap and pixels in the output bitmap. An error term (16) is used to link successive output pixel determinations. For each output value determination (28) the values of the mapped input pixels are added to the error term to create a test value (22) that determines what output is generated; the output value generated therefrom is then subtracted from the test value to create the next value of the error term (16). The conversion system is of particular advantage in converting an image having gray scale that is represented in a binary bitmap where gray scale is represented by the ratio of the number of ''on'' pixels to the number of ''off'' pixels. The present image conversion system performs a conversion such that the output bitmap represents such gray scale particularly well.
IPC 1-7
IPC 8 full level
B41J 2/485 (2006.01); G06F 3/12 (2006.01); G06T 3/40 (2006.01); G09G 5/36 (2006.01); H04N 1/40 (2006.01)
CPC (source: EP US)
G06T 3/40 (2013.01 - EP US); H04N 1/40068 (2013.01 - EP US)
Designated contracting state (EPC)
BE DE FR GB
DOCDB simple family (publication)
WO 8800377 A1 19880114; AU 646002 B2 19940203; AU 6803890 A 19910314; CA 1274021 A 19900911; DE 3687460 D1 19930218; DE 3687460 T2 19930429; EP 0270534 A1 19880615; EP 0270534 A4 19900123; EP 0270534 B1 19930107; JP 2635034 B2 19970730; JP S63503529 A 19881222; US 4742553 A 19880503
DOCDB simple family (application)
US 8601365 W 19860626; AU 6803890 A 19901213; CA 536928 A 19870512; DE 3687460 T 19860626; EP 86904578 A 19860626; JP 50376186 A 19860626; US 574586 A 19860626